/Engine/Source/Runtime/Core/Public/Math/GenericOctree.h
This function will traverse the Octree using a fast box-box intersection this should be the preferred way of traversing the tree.
template<typename IterateBoundsFunc> void FindElementsWithBoundsTest ( const [FBoxCenterAndExtent](API\Runtime\Core\Math\FBoxCenterAndExtent) & BoxBounds, const IterateBoundsFunc & Func ) const